JsDeprecationTestController.php

<?php

declare (strict_types=1);
namespace Drupal\js_deprecation_test\Controller;


/**
 * Test Controller to show message links.
 */
class JsDeprecationTestController {
    
    /**
     * Renders page that has js_deprecation_test/deprecation library attached.
     *
     * @return array
     *   Render array.
     */
    public function jsDeprecationTest() {
        return [
            '#attached' => [
                'library' => [
                    'js_deprecation_test/deprecation_test',
                ],
            ],
        ];
    }

}